Skin function is largely dependent on SC water balance. Animal skin is frequently used as an alternative to human skin in percutaneous absorption studies. Porcine skin is a well-accepted and readily available model of the human skin barrier. It is important to assess how similar porcine skin water permeability is to that of human skin to confirm the validity of the model. Moisture absorption/desorption isotherm curves for human and porcine SC were obtained. The apparent diffusion coefficients of porcine SC calculated were slightly smaller than that of human SC. Besides, when SC thickness was considered, diffusion coefficients were obtained, with porcine SC having a significant higher permeability. The higher thickness of the porcine SC compensates its higher diffusion per thickness unit, leading to similar apparent diffusion coefficients, thus indicating the suitability of the porcine SC for the skin permeation studies. (C) 2014 Elsevier B.V. All rights reserved,